Winding devices and methods for winding strips of material, particularly metal strips, on the rotary mandrel of a winding machine are known. Some of these devices are incorporated in the mandrel of the winding machine and consist of a longitudinal groove in the mandrel in which the end of one or more strips is introduced, the groove internally comprising jaws holding the ends of the strips. When the mandrel rotates for winding, it pulls the strips along and winds them on its surface.
Other devices for winding a strip are the so-called belt wrappers, consisting of mechanisms outside the mandrel of the winding machine, the mechanisms comprising an opening with a rough belt coupled to the mandrel. When the end of the strip or strips is arranged on the surface of the mandrel, the belt wrapper device is coupled, and when the mandrel starts to rotate, the strip is arranged between the surface of the mandrel and the belt of the device which also rotates in the same direction as the strip. The belt wrapper device therefore prevents backward movement of the strip and aids in winding same in the first turns thereof. The mandrel therefore lacks grooves on its surface and the end of the strip is not folded.
Document KR2013120927 A describes a winding device for winding a strip on a rotary mandrel of a winding machine, comprising a pressure assembly pressing the strip against the surface of the mandrel when winding the strip. The pressure assembly comprises a first pressure unit which is coupled to the shaft of the mandrel and rotates together with the mandrel, from a first winding position to a second winding position in the intersection with the strip, while the first pressure unit presses on the strip, and a plurality of additional pressure units pressing on the strip from different fixed angular positions with respect to the mandrel.